Infusion set

ABSTRACT

A device for inserting a cannula into tissue, including a cannula, a protective element which can accommodate said cannula, an operating element for moving the cannula out of the protective element, and a holder fixedly connected to the cannula. The invention encompasses a system for connecting a liquid supply to the cannula.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of International Patent ApplicationPCT/CH02/00186, filed on Apr. 3, 2002, which claims priority to GermanApplication No. 101 17 285.0, filed on Apr. 6, 2001 and GermanApplication No. 201 10 059.2, filed on Jun. 19, 2001.

The present invention relates to an infusion set, in particular to adevice for inserting a cannula into tissue, for example skin tissue,fatty tissue or muscle tissue, and to a device for supplying a liquidvia the cannula into the tissue.

A device for inserting a catheter comprising a needle is known from EP 0451 040 A1, wherein a cover is provided which may be pushed togetherover the needle. The catheter can thus be inadvertently removed even bysmall drag forces acting on the catheter, and lies open, relativelyunprotected, at the injection point; see FIG. 1 in EP 0 451 040 A1.

EP 0 290 176 A1 discloses a device for inserting a cannula comprising aneedle, wherein the needle has to be pressed against a spring when beinginserted and is retracted by the spring force into a casing after theinsertion process. Here, too, the cannula is relatively unprotected onceinserted, and can easily be inadvertently removed.

A device for subcutaneously supplying a medicine is known from EP 0 615768 B1. A cannula comprising a needle is inserted, wherein at the sametime as the cannula is inserted, an arrangement connected fixedly to thecannula and having an adhesive underside is applied to the skin, whichmakes the injection process, which is often unpleasant for the user,additionally difficult.

In the known devices, the cannula is either relatively unprotectedagainst being unintentionally removed, a drag force acts on the cannulainserted into the tissue even as the needle is removed from the cannula,or an additional device has to be moved together with the cannula duringthe injection process, which makes positioning it exactly difficult.

It is an object of the present invention to provide a device whichimproves the insertion of a cannula. In general terms, an infusion setis provided which exhibits improvements with respect to the prior art.

A device in accordance with the invention for inserting a cannula into atissue, in some embodiments preferably for subcutaneously ortranscutaneously administering a liquid, comprises a cannula which, inone embodiment, is formed as a hard cannula, such that it can beinserted into the tissue without an additional needle or other injectionelement, e.g., by absorbing liquid, wherein the cannula is preferablyelastic or flexible once it has been inserted into the tissue. It is,however, also possible to provide a known cannula which is inserted intothe tissue in a known way, using, for example, a guiding needle or otherinjection element. Furthermore, a protective element is provided whichcan accommodate the cannula before it is inserted into the tissue,wherein the protective element is preferably formed such that the tip ofthe cannula, or also of a needle suitable for inserting the cannula,which penetrates into the tissue is covered by the protective elementsuch that a user cannot inadvertently come into contact with said tipand be injured by said tip.

In some embodiments, the protective element can surround the tip of thecannula partially or completely or can surround the entire cannula, or aneedle provided for inserting the cannula as the case may be, in orderto guarantee the protective function. Furthermore, an operating elementis provided whereby the cannula or needle and cannula can be moved outof the protective element, in order to insert the cannula into thetissue. In some embodiments, if a needle is used, it is preferable if,once the cannula has been inserted, the needle can be moved back intothe protective element again, using the operating element or alsoautomatically, e.g., using a spring mechanism, in order to also minimiseor rule out the danger of injury once the cannula has been inserted.

In some embodiments, in accordance with the invention, the cannula isconnected to a holder which can be provided at the distal end, i.e., theend facing away from the tip of the cannula. In some embodiments, theholder can be moved with the cannula and, when inserting the cannula,can fix the cannula in a fixed position, for example by latching—or moregenerally, connecting—said holder to a foundation body, already fixedlyarranged over the injection point before the cannula is injected. If,for example, a needle is removed from a cannula after said cannula hasbeen inserted, then it is possible due to the holder connected to thecannula to ensure that when a holding force is applied to the holder,e.g., by connecting the holder to a foundation body, the removing forceof the needle does not act directly on the cannula, i.e., the cannula isnot strained in the extraction direction when it is extracted.

In accordance with the invention, it is possible to relieve the cannulawhen extracting a needle by suitably holding and/or fastening theholder, and to secure the cannula against being unintentionally removed.If a cannula is inserted without using a needle, then the holder inaccordance with the invention exhibits the advantage that the insertedcannula can be secured against being unintentionally removed, by theholder and as the case may be by an element connected to the holder.Using the device in accordance with the invention, the injection processmay be simply and relatively safely performed.

Although this description talks of “expelling” a needle or cannula usingan “expelling element,” it should be noted that this is also intended tomean removing using a drag element, i.e., a movement can be caused by adrag and/or pressure force or a drag or pressure spring.

The holder connected to the cannula is advantageously formed such thatit can establish a connection with another element, preferably a basebody which may be adhered to the skin above an injection point, saidbase body advantageously being arranged such that it connects with theholder when the cannula is completely or almost completely expelled.This connection can be a latch connection, wherein one or more groovesor recesses and/or projections or latching edges can be provided on theholder, enabling a detachable or non-detachable fixed connection betweenthe holder and a suitable element. Other suitable connections orconnective structures may be used as well.

In a preferred embodiment, a needle is provided using which the cannulacan be inserted into a tissue, wherein the needle is advantageouslysurrounded by the cannula. It is particularly advantageous to design thedevice such that, once the cannula has been inserted, the needle can bere-inserted, in some embodiments preferably completely, back into theprotective element, e.g., by a movement of an operating element and/or aspring which is compressed when the cannula is inserted into the tissueand the needle is extended out of the protective element and generates aforce which moves the needle back to its initial position in theprotective element.

In some embodiments, the device is preferably designed such that it canbe fixedly or detachably connected to a base body and, particularlyadvantageously, is already connected to the base body in an initialstate, such that application or use is simplified for the user. The basebody can consist of a plaster which may be adhered to a point on theskin and a foundation body arranged on said plaster, on which foundationbody the device for inserting the cannula is arranged. In such aconfiguration, the tip of the cannula or needle can be arranged actuallyrelatively near to an exit opening of the base body, such that once theplaster has been adhered to an area of skin, the cannula or needle canbe immediately inserted into the skin. The tip of the cannula or needlecan also protrude out of the protective element without there being adanger of injury for a user, since the tip is shielded by thesurrounding base body. Advantageously, the passage opening provided inthe base body for the tip of the cannula or needle is relatively small,preferably only slightly larger than the diameter of the cannula, inorder to rule out the possibility of the user reaching through thepassage opening, thus minimising the danger of injury. Once the cannulahas been inserted, and the needle retracted into the protective element,the device can be detached again from the base body, such that a fluidsupply can be connected to the cannula.

In some preferred embodiments, the device for inserting the cannula canbe connected to the base body, particularly to the foundation body via aconnecting element, such as a latch connection which preferably can alsobe detached.

In a preferred embodiment of the invention, the protective element is aframe which at least partially surrounds the cannula or needle when theyare retracted. In one embodiment, the protective element is a sheathwhich completely surrounds the cannula or needle when they areretracted, wherein a passage opening is provided in the protectiveelement, through which the cannula or needle can be moved out of theprotective element and/or inserted back into the protective element.Said passage opening can be open and slightly larger than the outerdiameter of the cannula. It is also possible to seal the passage openingusing a suitable covering element which can be moved away from thepassage opening when the cannula or needle is extended or which isformed elastically such that the cannula or needle can pierce it.

The device is advantageously designed such that the operating element,or also a needle element provided for inserting the cannula, can—whenretracted and once the cannula has been inserted—be connected, inparticular latched, to the protective element, such that the needle isprevented from being inadvertently re-expelled from the protectiveelement and the possibility of a user being unintentionally injured isthus ruled out.

In one preferred embodiment, the device—in particular the operatingelement—is formed such that when the cannula is expelled, the device forinserting the cannula can be prevented from being detached from a basebody connected to the device. To this end, a transverse element which isconnected to the operating element and may be shifted can be provided,the transverse element preventing holding elements provided forconnecting to the base body from being pressed together when the cannulais expelled, thus enabling the possibility of loosening the device fromthe base body, which can only be achieved by pressing said holdingelements together, to be ruled out. In general terms, any arrangement orelement can be used which is able to offer such a securing function.This can ensure that the cannula inserting device is not inadvertentlydetached from the base body, when for example a needle is extended outof the protective element, which could lead to a user being injured.

In some embodiments, a sealing element or septum is preferably providedin the holder, for sealing the upper side of the cannula or a liquidspace, wherein said sealing element or septum can be penetrated by aneedle and/or a liquid supply and can guarantee a liquid-proofconnection. If an element is not inserted into the septum, then it cancompletely seal the access to the cannula or a liquid space lying abovethe cannula. Suitable materials for this are known in the prior art.

In accordance with another aspect of the invention, a base body isprovided which consists of a plaster which may be adhered to a point onthe skin and a foundation body arranged on said plaster, wherein thebase body or foundation body comprises at least one detachableconnecting element to which the device described above for inserting acannula can be attached and to which a device for supplying a fluid orliquid can be attached, such that when the base body is attached abovean insertion point of the cannula, both the device for inserting thecannula and a device for supplying a fluid can be attached, together orin succession, to the same or to different connecting elements on thebase body. In some preferred embodiments, the device for inserting thecannula can already be fixedly and detachably connected to the base bodyin its initial state, such that the base body together with theinserting device for the cannula can be attached to the above aninsertion point of the cannula, wherein once the cannula has beeninserted, the inserting device can be detached again from the base body.It is possible to connect to the base body to the cannula insertingdevice just before inserting the cannula.

The at least one connecting element provided on the base bodyadvantageously serves both to connect to the inserting device for thecannula and to connect to the device for supplying a fluid, such thatonce the inserting device for the cannula has been detached, the devicefor supplying the fluid can be attached to the same connectingelement(s) which previously served to fasten the inserting device forthe cannula.

In some embodiments, the at least one connecting element provided on thebase body is preferably an element which enables a latch connection,i.e., in particular a groove and/or latching edge or latching projectionusing which a latch connection with the inserting device for the cannulaand/or the fluid supplying device can be established.

In accordance with another aspect of the present invention, a system isproposed using which a liquid supply can be connected to a cannula,wherein a foundation body is provided which comprises a cannula which isalready inserted into a tissue, e.g., using the device described above.The foundation body has at least one opening which is connected to thecannula or the hollow space of the cannula. For supplying the liquid, aplug comprising a supplying element is provided which can be insertedinto the opening of the foundation body, such that the liquid can bechannelled via the supplying element through the opening of thefoundation body into the hollow space of the cannula and thus into thetissue. In accordance with the invention, the plug can be attached to acontact point of the foundation body and tilted around the contact pointsuch that the supplying element of the plug is guided into the openingof the foundation body. Connecting the plug of a liquid supply to thecannula in this way is advantageous since no exact positioning isrequired at the beginning of the connecting process, i.e., users who arerestricted in their physical capacity, for example, can attach the plugto a contact point of the foundation body relatively easily, wherein thecontact point need not be a point in the geometric sense but rather canalso be formed as a contact edge having a linear or also curved orangled run, or as a contact area. If such a plug having a contact edgeor a suitable protrusion of the plug is attached to a contact edge ofthe foundation body, which does not yet require great precision withrespect to the contact position, then the plug can be gradually moved tothe exact position by tilting around said contact edge, for exampleusing suitable guides, such that the supply element can be insertedexactly into the opening of the foundation body when the plug is tiltedcompletely down. Connecting a plug to the foundation body in this way isthus relatively fault-tolerant with respect to attaching the plug to thefoundation body, and is greatly advantageous particularly when thecannula connected to the foundation body has been introduced using aninserting device already fixedly connected to the foundation body, asdescribed above. In this case, once the cannula has been inserted, theinserting device for the cannula merely has to be detached from thefoundation body by the user, which does not require an exact positioningprocess, such that the only positioning process which has to beperformed by the user is the fault-tolerant attaching of the plug to thecontact point of the foundation body, wherein the supplying element ismoved positionally exactly to the opening of the foundation body,preferably via a suitable guide while tilting the plug.

In some preferred embodiments, at least one guiding element is providedon the foundation body and/or the plug, in order to guide the plugduring the tilting process once it has been attached to the contactpoint or contact edge. For example, a channel tapering widthways can beprovided as the guiding element, with which a protrusion engages suchthat during the tilting process, the protrusion is guided along thechannel towards the narrower end, which enables the plug to be exactlypositioned relative to the foundation body. Both the channel and theplug can be provided on the foundation body and/or on the plug.Furthermore, it is also conceivable to provide lateral guides on theplug and/or foundation body, which are funnel-shaped in order toposition the plug relative to the foundation body as desired. Ingeneral, any arrangement is suitable which enables the plug attached toat least one contact point to be guided in a guiding process and thus tobe exactly positioned when it is tilted down.

In some embodiments, the plug is preferably formed such that it can jamwith the contact point or a contact edge of the foundation body. What ismeant by jam in the sense of the invention is that the plug abuts apoint or a number of points, edges or areas of the foundation body and aloose connection between the plug and the foundation body is thuscreated, which enables tilting or a rotational movement about thisconnection. Preferably, at least one degree of freedom in the movementof the plug relative to the foundation body is to be restricted, suchthat once the plug has been jammed into the foundation body, the plug isfirstly positioned roughly with respect to the foundation body.

In one preferred embodiment, the plug can be connected, e.g., latched orlocked, to the foundation body, wherein suitable grooves, latchingprojections or the like can be provided to this end. The connection orlatch connection can be designed to be detachable or non-detachable.

In accordance with another aspect of the invention, a foundation bodycomprises a rotatably mounted swivel which is fixedly connected to thefoundation body. The swivel has an opening, sealed by a sealing element,which enables a cannula including, for example, a needle, to beintroduced in a first position of the swivel and enables a supplyingelement for supplying liquid to be introduced in a second rotatedposition. Providing a swivel on the foundation body incurs the advantagethat if the opening of the swivel is aligned upwards, i.e., in adirection in which the opening lies on an extension of the desiredposition of the cannula to be inserted, the cannula can be insertedthrough the opening of the swivel and through the foundation body,directly into the tissue. Once the cannula has been inserted, and theinserting device of the cannula loosened as the case may be, the swivelcan be rotated such that a supplying element for supplying liquid can beconnected laterally or when the opening of the swivel is not pointingupwards. A cannula can thus be easily inserted and a liquid supply canbe connected laterally, which keeps the overall height of the device lowwhen the cannula is inserted and the liquid supply connected. Thecannula can be connected to the opening of the swivel by a flexible tubeelement or other suitable device which enables a secure connection whenthe swivel is rotated.

In accordance with another aspect of the invention, a device forsupplying a liquid into a tissue via a cannula comprises only onesealing element which serves to seal a liquid space and can be piercedby a cannula and/or a needle if the cannula is to be inserted into thetissue and can be penetrated by a supplying element if a liquid is to besupplied to the liquid space. In addition, other sealing elements can beprovided.

In accordance with one aspect of the invention, a liquid can be suppliedto a tissue via a cannula, wherein a cannula—in some instances, togetherwith a needle—pierces a sealing element in order to insert the cannulainto the tissue. If the cannula has been inserted, then a supplyingelement is inserted through the sealing element, once the needle hasbeen removed as the case may be, in order to insert a liquid into thetissue via the supplying element, through the sealing element and thecannula.

In accordance with another aspect of the invention, a device forinserting a cannula into tissue is provided, wherein a cannula expellingdevice for expelling the cannula and inserting the cannula into tissueis provided. In accordance with the invention, a restoring element iscoupled to the cannula expelling device in order to retract the cannulaexpelling device once the cannula has been expelled. In someembodiments, the restoring element is preferably a spring which can bebiased such that the energy or force stored in the spring is sufficientto retract the cannula expelling device back from its expelled state,wherein completely retracting the cannula expelling device into itsinitial state is possible but not required. In accordance with theinvention, the application of a cannula can thus be automated andtherefore simplified by suitably selecting the parameters of therestoring element, such as a spring length and/or a spring constant, therestoring process of the cannula expelling device can be securelyperformed. That is, when these parameters are selected, a sufficientforce is always available to securely retract the restoring element,without a user having to manually apply a large force.

In some embodiments, the cannula expelling device is preferably aguiding needle or other element bearing the cannula. A cannula without aguiding needle can thus for example be inserted by means of a suitablecannula holder.

In some preferred embodiments, a spring is provided as the restoringelement, but other energy-storing or force-storing elements can also beused in accordance with the invention in order to retract the restoringelement again, once the cannula has been inserted.

In some embodiments, a triggering element is preferably provided for therestoring element, wherein said triggering element can be operatedmanually or can be automatically triggered when the cannula insertingdevice is in a particular state. A push-button or other suitableswitching or sliding element can be provided as a manual triggeringelement, which can release a safety catch of the restoring element. Aholding element which locks the restoring element in the restoringdirection can be provided as the safety catch, wherein said holdingelement is shifted when the safety catch is triggered—for example, whena push-button is pressed—such that a restoring force is applied to thecannula expelling device via the restoring element, in order to retractit. The holding element can be a laterally shifting element such as apin or an edge, and can also be moved via a tipping or tiltingmechanism.

Advantageously, the triggering element for the restoring element can beautomatically triggered when the cannula inserting device is in aparticular state. In some embodiments, a mechanism can be provided whichautomatically initiates the restoring process of the cannula expellingdevice when the cannula inserting device is removed from a foundationbody. To this end, a cam can be provided on the foundation body, whereinsaid cam automatically operates a triggering mechanism for the restoringelement when the cannula inserting device is removed from the foundationbody.

An expelling element, for example a spring, can also advantageously beprovided, which can generate a sufficient force for inserting thecannula into the tissue. The expelling element can be secured asdescribed above for the restoring element and can likewise be triggeredby a push-button. When both a restoring element and an expelling elementare provided, a fully automatic cannula inserting device may be created,since a user does not have to actively apply a force, either to insert acannula or to retract a cannula expelling device. Inserting a cannula,for example using a guiding needle, and retracting the guiding needleare thus fully automated, such that the danger of users incorrectlyusing the device is reduced.

The device for inserting a cannula into tissue can advantageously bedesigned such that a single energy-storing element, such as a spring ora number of co-operating energy-storing elements, is used to move acannula expelling device or needle, preferably after having beensuitably positioned, automatically i.e., without supplying externalenergy, such that the cannula is inserted into the tissue and thecannula expelling device is then automatically moved back, likewisewithout supplying an external force or energy, such that the cannulainserted into the tissue is removed, such that a user substantially doesnot have to apply any force, except to trigger the respective expellingand restoring processes.

In some embodiments, when using a single energy-storing device, such asa pressure spring, it is then advantageous to arrange the spring tensedin its initial state, i.e., before the cannula is inserted into tissue,such that when the spring is firstly partially relieved or partiallyexpanded in a first direction, to expel the cannula expelling device orneedle downwards from the cannula inserting device, the cannulaexpelling device is moved out of the cannula inserting devicesufficiently far that the cannula or a cannula sub-assembly can bepositioned on the tissue as desired, wherein when the spring is secondlypartially expanded in a second direction, preferably opposite to thefirst direction, the cannula expelling device or needle is retractedagain, such that the cannula or cannula sub-assembly can remain in thetissue and the cannula inserting device, preferably with the cannulaexpelling device or needle completely retracted, can be removed. Insteadof a spring, which could be made of metal or plastic, other elements canalso be used as the energy store, for example elements which storepressurised air or elements based on electrical, magnetic or otherprinciples.

Preferably, a single triggering element is provided, such as for examplea button, switch, tilting mechanism, sliding mechanism, latchingmechanism, rotating mechanism, dial or lever, using which the expellingprocess and the restoring process of the cannula expelling device can betriggered, depending on its position. For example, a button can beprovided in the form of an element which may be inserted or pressed andwhich for example is pressed along a first partial distance, once asafety-release process has been performed, in order to trigger theexpelling process and is pressed in the same direction along a secondpartial distance having the same length or a different length, in orderto trigger the restoring process. Alternatively, it is also possible forthe one triggering element is operated in a first direction fortriggering the expelling process and is moved in a second direction fortriggering the restoring process of the cannula expelling device orneedle, said second direction being different to said first direction,such as for example a movement in the opposite direction. Thus, using asingle triggering element, such as for example a push-button, it ispossible in succession to first insert the cannula into tissue using thecannula expelling device or needle by pressing the push-button, forexample in a single direction, and then to restore the needle out of theinserted cannula or cannula sub-assembly, which enables the cannulainserting device to be operated very simply.

In general, a triggering element can also be formed as a rotatingmechanism or a dial, wherein an expelling process can be triggered byrotating and a restoring process by rotating further in the same oralternatively in the opposite direction. Combinations of differenttriggering elements are also possible, in order for example to triggeran expelling process using a push-button or switch and a restoringprocess using a dial. Advantageously, a triggering element for restoringis only released once expelling is complete.

Advantageously, at least one securing element is provided on the cannulainserting device, said securing element preventing a triggering elementfrom being unintentionally operated. Such a securing element may bedesigned such that it has to be removed from the cannula insertingdevice or moved to a safety-release position on the cannula insertingdevice, in order to be able to operate the triggering element at all.The securing element can be designed as a securing cap which at leastpartially and, preferably, approximately completely surrounds thetriggering element and protects it from being unintentionally touchedand thus from being undesirably triggered. Furthermore, the securingelement can also be designed as a device for blocking or arresting thetriggering element which has to be shifted first before in order to beable to operate the triggering element. It is then advantageous todesign the securing element such that it cannot simply be moved by anunintentional touch or a jolt, but rather can only be moved by apressing movement between two fingers to a position in which thetriggering element can be operated. The securing element can then bedesigned such that it either requires a constant pressure or drag inorder to move the triggering element to the safety-release position orremains in the safety-release position once a safety-release process hasbeen performed and locks in, such that the triggering element can beoperated once the safety has been released.

In some embodiments, the cannula inserting device can be designed as adisposable device in which the restoring element and/or expellingelement are already biased in order to automatically insert the cannulaand/or automatically restore the cannula expelling device. The cannulainserting device can, however, also be designed as a reusable cannulainserting device in which the restoring element and/or expelling elementare formed such that they may be loaded or tensed. Thus, a mechanism canbe provided for re-tensing a restoring spring and/or an expellingspring, after a cannula has been inserted and/or a cannula expellingdevice retracted, such that the cannula inserting device can be used toinsert another cannula.

In general, the cannula inserting device can, in accordance with theinvention, be designed to be fully automatic, i.e., both an expellingelement for the cannula and a restoring element can be provided.Alternatively, it is also possible to provide only one of these twoelements, in order to create a semi-automatic cannula inserting device,wherein the other process in each case then has to be performedmanually. It is possible to only automate inserting the cannula, byproviding an expelling element; retracting the cannula expelling devicemay then be performed manually.

Deviating from the exemplary latch connections described above, forconnecting the respective devices to a foundation body all the describedembodiments of an infusion set or cannula inserting device and/or aliquid supplying device can also comprise a rotational or screwconnection which can be latched in one or more positions, such that therespective devices can be connected to and/or detached from each otherby rotating, and the latch connections described may be omitted.

The devices described above in accordance with the individual aspects ofthe invention can be used both independently of each other and incombination with elements in accordance with other aspects of theinvention.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts a first embodiment of an infusion set, in accordance withthe invention, of a device for inserting the cannula, attached to a basebody;

FIG. 2 depicts the device in accordance with FIG. 1, wherein the cannulainserting device has been loosened from the base body;

FIG. 3 is a partial sectional view of the base body, with a cannulainserted;

FIG. 4 is a cross-sectional view of a liquid supplying device;

FIG. 5 is a partial cross-sectional view of the liquid supplying deviceto be inserted into the base body;

FIG. 6 depicts the arrangement in accordance with FIG. 5, with a plug ofthe liquid supplying device attached to the base body;

FIG. 7 depicts the arrangement of FIG. 6, from a different angle;

FIG. 8 depicts an alternative embodiment of the invention, comprising adial;

FIG. 9 depicts an embodiment of an automatic cannula inserting device,in its initial state;

FIG. 10 depicts the cannula inserting device shown in FIG. 9, after thecannula has been inserted;

FIG. 11 depicts the cannula inserting device shown in FIG. 10, after theguiding needle has been restored;

FIG. 12 depicts the cannula inserting device shown in FIG. 11, afterhaving been separated from the foundation body;

FIG. 13 depicts a first embodiment of an automatic cannula inserting andrestoring device, in its initial state;

FIG. 14 depicts the device of FIG. 13, after the cannula has beeninserted;

FIG. 15 depicts the device shown in FIG. 14, after the guiding needlehas been restored;

FIG. 16 depicts a second embodiment of an automatic cannula insertingand restoring device, in its initial state;

FIG. 17 depicts the device shown in FIG. 16, after the cannula has beeninserted;

FIG. 18 depicts the device shown in FIG. 17, after the guiding needlehas been restored.

DETAILED DESCRIPTION

FIG. 1 shows an infusion set including a cannula inserting device 3-8,fixedly pre-assembled to the base body 1, 2. The base body 1, 2 consistsof a foundation body 1 and a plaster 2 which exhibits an adhesive lowersurface in order to be able to adhere the base body over an injectionpoint. The foundation body 1 is arranged, e.g., adhered, on the upperside of the plaster 2 and is fixedly connected to the cannula insertingdevice 3-8 by the bracket 6 a. The cannula inserting device comprises aguiding needle 8 which is guided through the cannula 3 and using whichthe cannula 3 can be inserted into a tissue from the underside of thefoundation body 1. On the upper side of the cannula 3, i.e., the side ofthe cannula 3 facing away from the tip of the guiding needle 8, a holder5 is fixedly connected to the cannula 3, wherein a sealing element orseptum 4 is provided in the holder 5, as shown in FIG. 3. The guidingneedle 8 and the cannula 3 are surrounded by the guiding element 6 whichserves as a protective element, such that on one hand there is no dangerof injury to a user since the tip of the guiding needle 8 does notprotrude out of the arrangement shown and is still arranged within thefoundation body 1 or guiding element 6, and, on the other hand, thearrangement shown in FIG. 1 largely prevents the guiding needle 8 andthe cannula 3 from being contaminated before the cannula 3 is insertedinto tissue. The later advantage is provided since direct contactbetween the cannula 3 and the guiding needle 8 and the environment isprevented by the guiding element 6 and the foundation body 1. Theguiding needle 8 is fixedly connected to the operating element 7, asshown in FIG. 2, and can be expelled from the foundation body 1 bypressing downwards on the operating element 7, in order to insert thecannula 3 into a tissue.

FIG. 2 shows the arrangement of FIG. 1, after the cannula 3 has beeninserted and the connection between the cannula inserting device and thebase body has been released. By pressing the operating element 7downwards, the guiding needle 8 has been shifted downwardly togetherwith the cannula 3 and the cannula 3 has been inserted into a tissue(not shown) below the plaster 2. This has inserted the holder 5connected fixedly to the cannula 3, together with the sealing element 4within it, into the foundation body 1 until an annular protrusion 1 d ofthe foundation body 1 engages with a channel 5 a running around theholder 5 and thus latches the holder 5 into the foundation body 1. Oncethe holder 5 has been latched in the foundation body 1, the guidingneedle 8 can be removed from the cannula 3 by moving the operatingelement 7 upwards, without an excessively large force acting on theinserted cannula 3 during this process of removing the guiding needle 8from the cannula 3. Latching the holder 5 into the foundation body 1fixedly anchors the holder 5 in the foundation body 1 if an upward forcerelative to the guiding element 6, which is still connected to thefoundation body 1 during the removing process, acts on the guidingneedle 8, and thus enables the drag on the cannula 3 to be relievedduring the needle 8 removing process.

The outer area of the holder 5, which is guided in the interior of theguiding element 6, can exhibit a surface structure or comprise one ormore elements projecting outwards which enable the holder 5 to move inthe expelling direction but prevent or hamper it from moving in therestoring direction, such that incorrect use may be prevented.Accordingly, corresponding structures or elements can be provided on theinner side of the guiding element 6, in order to enable movement only ina predetermined direction.

If the brackets 6 a of the guiding element 6 are moved by pressing theoperating elements 6 b together, such that the latching projections 6 cof the guiding element 6 no longer engage with the latching projections1 a of the foundation body 1, then the cannula inserting device can bedetached from the foundation body 1. In its most extreme upper position,the operating element 7 is fixedly latched to a circumferentialprotrusion 6 d of the guiding element 6 via a circumferential groove 7 ain the lower region of the operating element 7 and thus ensures that,once the cannula inserting device has been disconnected, the guidingneedle 8 can no longer be unintentionally expelled from the guidingelement 6. In the basic pre-assembled state of the cannula insertingdevice on the foundation body 1, as may be seen from FIG. 1, theoperating element 7 is retracted far enough into the guiding element 6that the circumferential groove 7 a of the operating element 7 ispositioned below the circumferential protrusion 6 d, such that theoperating element 7 only latches to the guiding element 6 once thecannula 3 has been inserted. FIG. 3 shows a partial section of theinserted cannula 3, with the holder 5 latched in the foundation body 1,wherein a sealing element 4 is arranged in said holder 5.

FIG. 4 shows a sectional image of the plug 9 of the liquid supply deviceshown in FIG. 1. The coupling part 13 of the tube 12 is connected to aliquid conveying means (not shown). The entire liquid space of thecoupling part 13, the tube 12 and the plug 9 is then flooded. The plugcomprises a plug cannula 10 which is connected to the tube 12 by theconduit 9 a running through the plug 9. The plug 9 is moved to aposition above the foundation body 1 as shown in FIG. 5 and brought intocontact with the edge 1 b of the foundation body 1 via the edge 9 brunning along the lower rear side of the plug 9. The plug 9 ispreferably tipped slightly upwards for this, as shown in FIG. 6, suchthat the edge 9 b protruding from the plug 9 is inserted into the gapdefined by the upper side of the foundation body 1 and the jutting edge1 c of the foundation body 1. The plug 9 can thus be moved to a firstcontact position with the foundation body 1 in a relatively simple anduser-friendly way. If the edge 9 b of the plug 9 engages with the gapdefined by the edge 1 c of the foundation body 1, then the plug 9 can betilted downwards about the point of rotation defined by this engagement,in order to introduce the plug cannula 10 into the casing 5 through thesealing element 4 and thus to enable a liquid to flow from the liquidconveying means through the coupling part 13, the tube 12, the plug 9and the plug cannula 10 into the cannula 3 and thus into the surroundingtissue.

If the plug 9 is tilted downwards from the position shown in FIGS. 6 and7, it is guided via guiding cams 14 in order to introduce the plugcannula 10 into the casing 5 positionally exactly. By guiding the plug 9as it is tilted, by means of the guiding cams 14, it is possible tocorrect a lateral offset of the plug 9 relative to the foundation body 1such as may arise as the plug 9 is attached to the edge 1 b of thefoundation body 1, such that the plug cannula 10 can always be securelyintroduced into the casing 5.

When the plug 9 is completely tilted down, the plug cannula 10 havingbeen introduced into the casing 5, the latch devices 15 providedlaterally on the plug 9 latch with the latching projections 1 b of thefoundation body 1, shown in FIG. 2, which connects the plug 9 securelyto the foundation body 1.

FIG. 8 shows an alternative embodiment of the present invention. Aswivel 16, rotationally mounted in the foundation body 1, can be movedto a position in which the opening 18 of the swivel 16 points upwards.In this position, a cannula can be inserted into the foundation body 1with the aid of the guiding needle 8 which is protected by a frameserving as a protective element 6, as described above. Once the cannulahas been inserted, the guiding needle 8 can be removed again. The swivel16 can then be rotated on its side, as shown in FIG. 8, and preferablylatches to a latching projection 17 pointing upwards and arranged on thebase plane of the foundation body 1, which holds the swivel 16 securelyin its tilted down position. In this alternative embodiment, a plug 9can be attached laterally to the completely tilted down swivel 16, suchthat the plug cannula 10 running in the linear extension of the tube 12can be inserted into the opening 18, pointing to the side, of the swivel16. A latching device 15 attached to the plug 9 can then latch withsuitable counter pieces of the swivel 16.

In each of the embodiments described above, the plug 9 can bedisconnected again from the foundation body 1 by laterally pressing onthe regions lying above or to the side of the latching devices 15 of theplug 9. Once the plug 9 has been disconnected, the sealing element 4again completely closes access to the cannula 3.

FIG. 9 shows an automatic cannula inserting device in accordance withthe invention. With respect to describing the foundation body 1,together with the corresponding latch connections, and inserting thecannula 3, together with its holder 5 and sealing element 4, referenceis made to the description above. A needle carrier 27 which may be movedin the longitudinal direction of the guiding element 6 is provided inthe guiding element 6, said needle carrier 27 being fixedly connected tothe guiding needle 8. Alternatively, the guiding needle 8 can also bedesigned such that it can be coupled to the needle carrier 27, in orderfor example to be able to exchange the guiding needle 8. The needlecarrier 27 is situated in a retracted position and is biased by aninserting spring 21 abutting the front side of the needle carrier 27,said inserting spring 21 being supported against a supporting element 20provided roughly in the middle part of the guiding element 6 and biasingthe needle carrier 27, which is secured by the holding element 28 a, inthe expelling direction of the cannula 3. The holding element 28 a canbe released by a first triggering button 24. On the opposite side of thesupporting element 20, a restoring spring 22 is provided which pressesagainst a holding ring 23 which is secured by a holding element 28 b andcan be released by a second triggering button 25. The needle carrier 27runs in the longitudinal direction of the guiding element 6, through thetwo springs 21 and 22 and may be shifted through the supporting element20 and the holding ring 23 and comprises a holding element 27 a at itsrear end in order to prevent it from being able to pass completelythrough the holding ring 23. If the triggering button 24 is pressed,then the schematically drawn holding element 28 a is slide or tiltedradially outwards in the direction of the arrow, the tilting mechanismpreferably being formed completely within the guiding element 6, whereinthe needle carrier 27 is then no longer held in the expelling directionof the cannula 3 and is accelerated downwards by the force of theinserting spring 21 in order to expel the cannula 3 from the guidingelement 6 via the guiding needle 8 and to insert it through the plaster2 into a tissue. The expelling movement is continued until the holdingelement 27 a of the needle carrier 27 abuts the holding ring 23.

FIG. 10 shows the cannula inserting device shown in FIG. 9, once theprocess of expelling the cannula 3 has been completed. The insertingspring 21 has transferred the energy stored in it to the needle carrier27 and is relieved. The holder 5 can, for example, be latched to thefoundation body 1 as described above. If the second triggering button 25is then operated by the user, the holding element 28 b which may beradially shifted (FIG. 9) is pushed out of the holding ring 23 and theholding ring 23—which has so far been secured against moving axially inthe guiding element 6—is released, such that the restoring spring 22presses against the holding ring 23 and the holding element 27 a of theneedle carrier 27 and a restoring force thus acts on the needle carrier27. In the embodiment shown, the restoring spring 22 is preferablydesigned such that it can apply a stronger force than the insertingspring 21, since the latter is pressed together again as the needlecarrier 27 is retracted. Alternatively, the needle carrier 27 can alsobe formed such that, once the cannula 3 has been inserted, there is nolonger a coupling between the lower side of the needle carrier 27 andthe inserting spring 21, such that the inserting spring 21 no longer hasto be tensed as the needle carrier 27 is retracted.

In general, the holding element 28 a and/or the holding element 28 b canbe formed as a tipping or sliding mechanism or as any other securingmechanism.

FIG. 11 shows the cannula inserting device shown in FIG. 10, once theneedle carrier 27 has been retracted. The guiding needle 8 has thus beenretracted back out of the expelled cannula 3 and inserted back into theguiding element 6, in order to avoid injuries.

As an exemplary alternative to the embodiment shown, the needle carrier27 can be retracted fully automatically, once the cannula 3 has beeninserted, by operating a triggering mechanism for the restoring spring22 via the underside of the needle carrier 27, which retracts the needlecarrier 27 back immediately after the cannula 3 has been inserted. Inthis case, the second triggering button 25 can be omitted.

In accordance with another alternative embodiment, the restoring spring22 can be triggered automatically by releasing the holding ring 23, whenthe cannula inserting device is removed from the foundation body 1,e.g., by simultaneously releasing the holding ring 23 when pressing inthe buttons 6 b in order to release the latch between the latchingprojections 6 c of the guiding element 6 and the latching projections 1a of the foundation body 1.

The cannula inserting device is advantageously designed such that thelatch between the guiding element 6 and the foundation body 1 cannot bereleased if the guiding needle 8 is in the position shown in FIG. 9before the cannula 3 is expelled and/or in the expelled position shownin FIG. 10. This can be achieved if, for example, the underside of theneedle carrier 27 is sufficiently wide that the underside of the guidingelement 6 is prevented from being pressed together at the buttons 6 b,and the latch between the guiding element 6 and the foundation body 1cannot therefore be released in the position shown in FIG. 10.

FIG. 12 shows the cannula inserting device, detached from the foundationbody 1, with the guiding needle 8 retracted. The cannula insertingdevice can now be safely disposed of, since the guiding needle 8 iscovered by the surrounding guiding element 6 and the danger ofunintentional pricking injury is minimized. Alternatively, the cannulainserting device can be moved back to the position shown in FIG. 9 usingtensing devices (not shown), for example by pushing the holding ring 23from its upper position back into a lower position, wherein therestoring spring 22 is re-tensed. It is equally possible to expel theneedle carrier 27 from the guiding element 6 and thus tense therestoring spring 22, wherein the inserting spring 21 is then re-tensedin a second step. In the case of a reusable device, the used guidingneedle is preferably exchanged and replaced with a new guiding needle,and a new cannula 3 and corresponding holder 5 including sealing element4 as the case may be.

FIG. 13 shows a first embodiment of an automatic cannula inserting andrestoring device, in its initial state before a cannula 3 on a cannulasub-assembly 35 has been inserted using a guiding needle 8. The cannulainserting device comprises a connector sleeve or guiding element 38which has connector elements 39 at its lower end, in order for exampleto be fastened on a foundation or base body 1, as shown for one of theembodiments in the figures above. Said connector elements 39 forconnecting the connector sleeve 38 to a predetermined base body comprisefor example latching tongues 39 a and other connecting elements (notshown). Within the connector sleeve 38, the guiding sleeve 33 isprovided with tongues 33 a, 33 b and 33 c protruding inwards from it.The tongues 33 a to 33 c are arranged at various positions in the axialdirection of the guiding sleeve 33 and can be arranged as individualprotruding elements or also over a large part of the circumference ofthe guiding sleeve 33. The tongues can also for example lie oppositeeach other and/or can be formed symmetrical with respect to each otheras a number of individual tongue elements. The three tongues 33 a to 33c shown by way of example are arranged offset with respect to each otherin the axial direction of the guiding sleeve 33, in order to fulfilvarious functions when an expelling and restoring process is triggered,as will be explained below. A triggering sleeve 37 a, fixedly connectedto the triggering button 37, is provided within the guiding sleeve 33,said triggering sleeve 37 a comprising indentations in the axialdirection which are assigned to the tongues 33 b and 33 c. Furthermore,special triggering surfaces, such as chamfers, are provided on thetriggering sleeve 37 a in order to press away the tongues 33 a to 33 cin a predetermined order when the triggering sleeve 37 a in theembodiment shown in FIG. 13 is shifted downwardly, initiating theexpelling and restoring process of the cannula sub-assembly 35.Furthermore, a needle part or needle carrier 34 is arranged, such thatit may be shifted, within the connector sleeve 38, and is coupled to thecannula sub-assembly 35 via a fixedly connected guiding needle 8 and adirect contact area or is latched to the cannula sub-assembly 35 via asuitable latching device (not shown). In the initial state shown, thecompletely biased spring 31 presses on the cannula sub-assembly 35,wherein a pair of tongues 33 b arranged symmetrically above the spring31 and a pair of tongues 33 a of the guiding sleeve 33 arranged belowthe cannula sub-assembly 35 hold the biased spring 31 pressing on thecannula sub-assembly 35 in position. A securing clip 38 a with a bore 38b is provided on the upper side of the connector sleeve 38, wherein thediameter of the bore 38 b roughly corresponds to the diameter of thetriggering button 37 and is preferably a little larger in order toenable the triggering button 37 to pass easily through. Theapproximately L-shaped securing clip 38 a lies opposite a securing clip38 c comprising an elastic element on the upper side of the connectorsleeve 38, wherein a tongue 38 d provided on the securing clip 38 a canlatch with the securing clip 38 c when the securing clip 38 a and thesecuring clip 38 c are pressed together. The bore 38 b shown in FIG. 13,arranged eccentrically with respect to the cannula axis, prevents thetriggering button 37 from being pressed. If the securing clip 38 a andthe securing clip 38 c are pressed together such that the securing clip38 c locks in for example with the tongue 38 d, then the bore 38 b ismoved to a concentric position with respect to the position of thetriggering button 37, such that the triggering button 37 can be pressed.

FIG. 14 shows the device shown in FIG. 13 once the operating button 37has been pressed in by about a half length. The lower tongues 33 a,which the cannula sub-assembly 35 has been pressed onto by the spring31, are deformed by the triggering sleeve 37 a extending along the innerside of the connector sleeve 38, which releases the cannula sub-assembly35 together with the needle carrier 34, the spring 31 pressing on alower end stopper which can be provided in the cannula inserting deviceor on a base body 1. The upper end of the needle carrier 34 thus leadsover the tongues 33 c. The cannula 3 of the cannula sub-assembly 35,connected to the guiding needle 8, is expelled downwards, out of thedevice, by the force of the spring 31, preferably at high speed, and canbe inserted into a tissue as desired.

In the position shown in FIG. 14, the cannula sub-assembly 35 is latchedto a foundation body or base body of an infusion set (not shown) and theneedle carrier 34 is unlatched by tongues in the foundation body of theinfusion set, such that the needle carrier 34 and the cannulasub-assembly are no longer connected (not shown in FIG. 14). In thisposition, the needle carrier 34 is latched by the two tongues 33 c,arranged symmetrically with respect to each other, which makes itpossible to re-position the set.

The semi-relieved spring 31 presses downwards against the expelledcannula sub-assembly 35 and abuts a protruding element of the needlepart 34 on the opposite side, the needle part 34 being secured againstshifting axially by the tongues 33 c. In the position shown, the spring31 is held by the tongues 33 b. In general, the spring can also be heldin the position shown for example by the upper end of the needle part34.

FIG. 15 shows the device from FIG. 14 once the operating button 37 hasbeen completely pressed in. This pushes the triggering sleeve 37 a overthe tongues 33 b and 33 c, which are pressed outwards and away and thusrelease the needle part 34 which is pushed back into the connectorsleeve 38 again by the spring 31 which can now be fully relieved. Thisretracts the guiding needle 8 connected to the needle part 34 out of thecannula and the cannula sub-assembly 35 into the connector sleeve 38,wherein the cannula 3 can remain in a tissue. The needle part 34 is heldin the retracted position by the spring 31, such that the guiding needle8 cannot unintentionally exit the connector sleeve 38, which minimisesthe risk of injury. The connector sleeve 38 can then be removed from abase body by detaching the connector elements 39.

FIG. 16 shows a second embodiment of an automatic cannula inserting andrestoring device in its initial state, comprising a connector sleeve 38which is connected to a foundation body 1. A triggering button 37 passesinto the triggering sleeve 37 a arranged within the connector sleeve 38.The triggering sleeve 37 a recesses and lower and upper chamfers on theinner side along its axial direction, using which a lower and an upperslaving ring 32 a and 32 b can be uncoupled when the triggering sleeve37 a is shifted axially, in order to expel the guiding needle 8,together with the cannula 3 arranged around it and the correspondingcannula sub-assembly 35, out of the connector sleeve 38 and to thenretract the guiding needle 8 out of the cannula 3 and the cannulasub-assembly 35, as will be described below.

The lower slaving ring 32 a abuts a stopper sleeve 36 and is held inposition by the stopper sleeve 36 against the pressure of the spring 31.The spring 31 presses on the upper side against the upper slaving ring32 b which is held in position, for example in a channel or recess, bythe guiding sleeve 33. The needle carrier 34 is designed such that itcan be moved in the axial direction of the connector sleeve 38, throughthe slaving rings 32 a and 32 b, up to the end of the needle carrier 34which exhibits a larger diameter than the inner diameter of the slavingrings in order for example to prevent the needle carrier 34 from fallingout. The needle carrier 34 is in turn fixedly connected to the guidingneedle 8.

FIG. 17 shows the device shown in FIG. 16 once the securing cap arrangedover the triggering button 37 has been removed and the triggering button37 has been pressed in by about a half length. The lower slaving ring 32a is laterally shifted away from the stopper sleeve 36 by a loweroblique inner surface of the triggering sleeve 37 a and thus uncoupledfrom the stopper sleeve 36. The lower slaving ring 32 a can eitheralready be coupled to the needle carrier 34 or can be coupled to theneedle carrier 34 by this shifting process. The spring 31 then pressesagainst the upper slaving ring 32 b which is still held fixedly by theguiding sleeve 33 and presses the lower slaving ring 32 a coupled to theneedle carrier 34 downwards and thus inserts the guiding needle 8,together with the cannula 3, into a tissue lying below the foundationbody 1, wherein the cannula sub-assembly 35 is in turn moved as far as alower end stopper. In this position, the needle carrier 34 remainslatched to the foundation body 1, which makes it possible to re-positionthe entire set.

FIG. 18 shows the device shown in FIG. 17 once the triggering button 37has been pressed in further. This firstly unlatches the needle carrier34 completely from the cannula sub-assembly 35. The upper slaving ring32 b is laterally shifted by a upper oblique area of the triggeringsleeve 37 a and thus uncoupled from the guiding sleeve 33 and couplesinto the needle carrier 34, such that the spring 31 can press the needlecarrier 34 upwards via the upper slaving ring 32 b, as far as an upperend stopper. This retracts the guiding needle 8 out of the cannula 3 andthe cannula sub-assembly 35, which is held in the retracted position bythe spring 31 pressing against the needle carrier 34, which minimisesthe risk of injury. In general, one or more operating elements, e.g.,buttons, can be provided for triggering the expelling and restoringprocesses, wherein said operating elements trigger, e.g., by releasing aspring, the corresponding process directly or indirectly, e.g., byshifting an element in the cannula inserting device.

In the foregoing description, embodiments of the invention, includingpreferred embodiments, have been presented for the purpose ofillustration and description. They are not intended to be exhaustive orto limit the invention to the precise form disclosed. Obviousmodifications or variations are possible in light of the aboveteachings. The embodiments were chosen and described to provide the bestillustration of the principals of the invention and its practicalapplication, and to enable one of ordinary skill in the art to utilizethe invention in various embodiments and with various modifications asare suited to the particular use contemplated. All such modificationsand variations are within the scope of the invention as determined bythe appended claims when interpreted in accordance with the breadth theyare fairly, legally, and equitably entitled.

1. A device for inserting a cannula into tissue, comprising. a) acannula; b) a protective element which can accommodate said cannula; c)an operating element, using which the cannula can be moved out of saidprotective element; and d) a holder which is fixedly connected to thecannula.
 2. The device as set forth in claim 1, wherein said holdercomprises a connecting element.
 3. The device as set forth in claim 1,further comprising a needle surrounded by the cannula.
 4. The device asset forth in claim 3, wherein said needle can be inserted completelyinto the protective element.
 5. The device as set forth in claim 3,wherein a spring or operating element is provided which generates aforce on the needle in an inserting direction into the protectiveelement.
 6. The device as set forth in claim 1, wherein the device isconnected to a base body, wherein the connection is detachable.
 7. Thedevice as set forth in claim 6, wherein said base body consists of afoundation body arranged on a plaster.
 8. The device as set forth inclaim 7, wherein the device comprises at least one connecting elementfor connecting to said foundation body.
 9. The device as set forth inclaim 1, wherein the protective element is a solid, non-ductile body.10. The device as set forth in claim 1, wherein the protective elementis a frame which at least partially surrounds the cannula when it isretracted.
 11. The device as set forth in claim 1, wherein theprotective element is a sheath which completely surrounds the cannulawhen it is retracted.
 12. The device as set forth in claim 1, whereinsaid operating element is connected to the protective element whenretracted.
 13. The device as set forth in claim 12, wherein theoperating element is formed such that it prevents the connection to thefoundation body from being released before the cannula is expelled. 14.The device as set forth in claim 1, wherein a sealing element isprovided in the holder.
 15. A base body comprising a foundation bodyhaving at least one connecting element for connecting to the device forinserting a cannula as set forth in claim 1 and for connecting to adevice for supplying a fluid.
 16. The base body as set forth in claim15, wherein said base body is connected to said device for insertingsaid cannula and the operating element is inserted at least partiallyinto the protective element.
 17. The base body as set forth in claim 15,wherein the same connecting element can be used for connecting to thedevice for inserting a cannula and to the device for supplying thefluid.
 18. The base body as set forth in claim 15, wherein said at leastone connecting element is a latching connecting element.
 19. A systemfor connecting a liquid supply to a cannula, comprising: a) a foundationbody comprising a cannula and an opening adjacent to said cannula; andb) a liquid supply comprising a plug having a supplying element whichcan be inserted into said opening of said foundation body, wherein saidplug can be attached to a contact point of the foundation body andtilted about said contact point such that said supplying element of theplug is guided into the opening of the foundation body.
 20. The systemas set forth in claim 19, wherein at least one guiding element isprovided on one of the plug and the foundation body in order to guidethe plug during tilting.
 21. The system as set forth in claim 19,wherein the plug is formed such that it can jam with the contact pointof the foundation body.
 22. The system as set forth in any one of claim19, wherein the plug can be connected to the foundation body.
 23. Afoundation body comprising a rotationally mounted swivel having anopening which enables a cannula including a needle to be introduced in afirst position and enables a supplying element for supplying liquid tobe introduced in a second rotated position.
 24. A device for supplying aliquid via a cannula into tissue, comprising a sealing element whichserves to seal a liquid space and can be pierced by the cannula when thecannula is to be inserted into said tissue and can be penetrated by asupplying element when a liquid is to be supplied to said liquid space.25. A device for inserting a cannula into tissue, comprising: a) acannula; b) a cannula expelling device for moving said cannula; and c) arestoring element which is coupled to the cannula expelling device, inorder to retract said cannula expelling device again once the cannulahas been expelled.
 26. The device as set forth in claim 25, wherein thecannula expelling device is a needle.
 27. The device as set forth inclaim 25, wherein said restoring element is a spring element.
 28. Thedevice as set forth in claim 27, wherein a triggering element isprovided for the restoring element such that the restoring element canbe automatically triggered, in particular when the cannula insertingdevice is detached from a foundation body connected to it.
 29. Thedevice as set forth in claim 25, wherein the cannula expelling devicefurther comprises a spring.
 30. The device as set forth in claim 29,wherein said cannula expelling device and the restoring element areformed by a single element, in particular the spring.
 31. The device asset forth in claim 25, further comprising a triggering element forsecuring and triggering at least one of the cannula expelling device andthe restoring element.
 32. The device as set forth in claim 31, furthercomprising a securing element for arresting said triggering element. 33.The device as set forth in claim 1, wherein the device is a disposabledevice or a reusable device.
 34. The device as set forth in claim 1,wherein a rotational connection for connecting the cannula insertingdevice to a foundation body is provided.